THE RELIABILITY ANALYSIS OF SINGLY REINFORCED CONCRETE BEAMS USING BS 8110 CODE

Abstract

In this study, the reliability analysis of singly reinforced concrete beams at the limit states of flexure and shear using BS 8110 design codes was carried out. The reliability analysis was performed at load ratios of 0.75, 1.0 and 1.25 respectively. The limit state functions were developed in bending and shear based on BS 8110, The design points were obtained using Minitab 17.0. A full factorial method of design of experiment was used to generate the deferent combination of design parameters that influenced the performance of the beams in bending and shear. The statistics of the basic random variables were obtained from literature. The computer programs developed in MATLAB language were invoked to estimate the reliability indices corresponding to the limit state functions generated based on First Order reliability Method. It was shown that the reliability indices generally decreased with increasing in load ratio considering failure of the singly reinforced concrete beams in bending and shear for BS 8110. It was also shown that the reliability of the beam increased with increases in width of beam considering failure of the singly reinforced concrete beams in bending and shear for the design code used. It was also observed that the results of the BS 8110 design code is more safe and satisfactory in shear respectively. The result obtained also showed that the BS 8110 were generally safe and satisfactory at load ratio of 0.75 for width 250mm, 275mm and 300mm respectively. Also, the design results were safe in bending and shear and safe for widths of beams between 250mm to 300mm at load ratio of 1.0 and 1.25 respectively. The computer programs developed in MATLAB environment were easy to execute and user-friendly and it is therefore suitable for reliability analysis of structures.